1. Field of the Invention
The present invention relates to a chair, more particularly to a chair with an extendible footrest.
2. Description of the Related Art
A conventional chair includes a seat base, a seat disposed above the seat base, a footrest disposed frontwardly of the seat, a backrest disposed rearwardly of and pivoted to a rear end of the seat, and a linkage unit interconnecting the footrest and the seat. The linkage unit includes at least two pairs of pivotally connected crank arms which are movable between extended and retracted positions relative to the seat.
One disadvantage of the aforementioned conventional chair resides in that the crank arms of the linkage unit may accidentally clamp a user""s finger when the crank arms are disposed at the retracted position.
Therefore, the object of this invention is to provide a chair having a linkage unit that interconnects a seat and a footrest and that has a plurality. of crank arms provided with an arm spacer therebetween such that the crank arms will not clamp the user""s finger when the crank arms are disposed at a retracted position.
Accordingly, a chair of the present invention includes: a seat base; a seat mounted on the seat base, extending in longitudinal direction, and having left and right sides, front and rear ends, and a bottom; a backrest disposed rearwardly of and connected to the seat; a footrest disposed frontwardly of the seat; and a linkage mounting unit including left and right brackets fixed to the bottom of the seat and extending in the longitudinal direction. Each of the left and right brackets has opposite front and rear ends. A shaft is mounted rotatably on the rear ends of the brackets, and extends in a transverse direction relative to the longitudinal direction. An operating lever is secured to the shaft for turning the shaft. The chair further includes a linkage unit and an arm spacer. The linkage unit interconnects the seat and the footrest, and includes a pair of crank mechanisms disposed at the left and right sides of the seat, respectively. Each of the crank mechanisms includes a first crank arm having a rear end pivoted to the front end of a respective one of the brackets 21 and a front end opposite to the rear end thereof, a second crank arm having a front end pivoted to the footrest and a rear end pivoted to the front end of the first crank arm, a third crank arm fixed to and extending transversely from the shaft and having a pivot end distal from the shaft, and a fourth crank arm having opposite front and rear ends respectively pivoted to the footrest and the pivot end of the third crank arm such that rotation of the shaft via actuation of the operating lever results in turning of the third crank arm via the shaft, thereby permitting extension and retraction of the linkage unit relative to the seat between folding and extended positions. The first and second crank arms are spaced apart from and are generally parallel to the third and fourth crank arms. The arm spacer has a fixed end fixed to one of the first and fourth crank arms, and a pivot end that extends from the fixed end and that is pivoted to the other one of the first and fourth crank arms so that the first crank arm and the second crank arm cooperatively define a first gap in the longitudinal direction therebetween, and that the third crank arm and the fourth crank arm cooperatively define a second gap in the longitudinal direction therebetween when the linkage unit is positioned at the folding position, thereby preventing clamping of a user""s finger when the linkage unit is moved from the extended position to the folding position.